1. Field of the Invention
The present invention relates generally to an illumination device used in dermoscopy. More particularly, the invention comprises an improved apparatus for enhanced imaging and illumination of the skin for medical examination and treatment.
2. Background
When using surface illumination to view human skin in medical examination, a great deal of surface light is reflected from the top layer of skin. Hand held dermoscopy devices that use light along with magnification can utilize polarizers or liquid-glass interface to reduce surface reflection and see deeper in to the skin. Dermoscopy apparatuses that employ light polarization to aid in viewing human skin surfaces and deeper tissue and structures of the skin are known and described U.S. Pat. Nos. 7,006,223 and 7,167,243 both issued to Mullani, the substance of each of which is incorporated herein by reference. In addition, a dermoscopy device identified as Dermlite® DL3 device is manufactured and marketed by 3Gen, Inc. of San Juan Capistrano. In the Dermlite® DL3 hand held device, a series of light emitting diodes (“LEDs”) are concentrically positioned around a magnifying lens to assist in lighting of a magnified image. The device includes two sets of white light LEDs that can be activated independently; one set of twenty one (21) LEDs provides reduced glare cross-polarized light to aid in canceling the reflected light from the skin, whereas the other set of seven (7) LEDs provides non-polarized light for traditional immersion fluid dermoscopy or for simply employing non-polarized light. Both sets of LEDs can be operated independently or at the same time. Users of the Dermlite® DL3 can toggle between polarized and non-polarized light to provide an enhanced perspective of skin surface and lesions.
It is also well known that different colored light penetrates to different depths in human skin tissue. Specific color wavelengths are absorbed differently by different components of the skin tissue. Such use of colored LEDs in a dermatoscope is described in U.S. Pat. Nos. 7,027,153 and 7,167,244 both issued to Mullani, the substance of each of which is incorporated herein by reference. The previously identified references disclose the combined use of white LEDs, UV/blue LEDs (405 nm), green/yellow LEDs (565 nm) and orange/red (630 nm). Alternatively, the 7,027,153 and 7,167,244 references suggest the use of LEDs with 480 nm, 580 nm and 660 nm wavelengths. In addition, a dermoscopy device identified as Dermlite® II Multispectral dermoscopy device manufactured and marketed by 3Gen, Inc. of San Juan Capistrano, Calif. provides four sets LED's comprising white, blue light (470 nm) for surface pigmentation, yellow light (580 nm) for superficial vascularity viewing, and red light (660 nm) for viewing of pigmentation and vascularity with the deeper-penetrating red light frequency.
In related medical examination procedures, such as for viewing structures on the surface and beneath the skin, a further way to introduce more light in to the skin is to use side-transillumination techniques whereby the light source is caused to be in direct contact with the skin to transfer light directly into the skin. One such technique is known and taught in U.S. Pat. No. 5,146,923 issued to Dhawan, the substance of which is incorporated herein by reference. A combination of surface illumination, epiluminescence and transillumination apparatus and method is demonstrated in the Nevoscope™ product sold manufactured by Translite LLC. of Sugar Land, Tex. Another known apparatus and method of viewing vein structures beneath the skin employs the use of transillumination as described in U.S. Pat. No. 7,874,698 issued to Mullani the substance of which is incorporated herein by reference. U.S. Pat. No. 7,874,698 issued to Mullani describes the use of orange light between 580 and 620 nm for transillumination imaging of deeper blood vessels in skin tissue. However, the technology of transillumination is different than imaging skin with direct surface light. In transillumination, the light is directed into the skin by direct contact with the skin.
With respect to Dermatoscopes that use white light to image the skin, white light has a range of colors from Blue to Red. As such, the skin can be visualized up to 3 mm deep depending on the ‘color’ of the white light. White light used in known dermatoscopes are usually generated by white LEDs and unlike halogen bulb light, the light from these LEDs comprise a great deal of blue light in the spectrum of white light. This bluish tint to the white light makes the dermatoscope more sensitive to the top 1 mm of skin. When using the blue tinted white light in dermatoscopes, it is difficult to see the pigmentation structures in the deeply pigmented areas that are deep. For purposes of early skin cancer detection, viewing pigmentation structures is important for diagnosing cancerous lesions that may be hidden from view at a deeper depth when using blue tinted white light.
To aid in the early detection of skin cancers, the viewing of deeper structures of the skin in close proximity of the skin without the need to contact the skin directly with a light source, or penetrate the skin surface is beneficial for examination, diagnosis and treatment. As described above, polarized white light and colored lights for surface illumination is known. Also, the use of colors in the orange range spectrum is known with respect to translliumiation devices for viewing vein structures. However, there is a great need in the art for a dermoscopy device that can illuminate the skin with white light and/or light in a color range that is adapted to provide a more advantageous viewing of the skin and sub-surface skin structures to enable a more enhanced viewing of pigments and lesions found in the skin that will aid in a visual early detection of various types of skin cancer.